Knowing how to take compass bearings is one of the most vital skills every backcountry adventurer should learn. Doing so allows you to establish your whereabouts, plot a course, and navigate with accuracy in any terrain.
We all know that compasses display the four cardinal directions: north, south, west, and east. But using such vague indicators to negotiate our way through backcountry terrain not only invites confusion and mistakes, it could also lead to the odd disaster.
Given this, hikers, campers, and mountaineers alike should set aside a little time to learn about using a compass and taking compass bearings before venturing off into the wilds.
Luckily, learning this skill is easy to do, as demonstrated below in our easy-to-follow, step-by-step guide.
Ready to learn about compass bearings?
- Take a bearing by eye
- Adjust for magnetic declination
- Orient your map
- Capture a bearing
- Triangulate your position with accuracy
What You’ll Need to Follow This Tutorial
The materials required to read bearings in the field are a compass and a topographical map.
Compass
You can use either a baseplate or thumb model, whichever suits your preference. That said, baseplate compasses boast additional features not used in the thumb variety that make them more precise, better for plotting distances, and easier to use when taking a bearing.
Maps
The three most important things to consider when choosing your map are detail, revision date, and type.
As a general rule, it’s always a good policy to get your hands on the most detailed topo you can find (1:25000 or even 1:10000). This, of course, will allow you to navigate with more accuracy.
And because the magnetic declination value of specific areas changes over time, getting the latest version is critical for effective and accurate navigation.
Finally, it should go without saying that the type of map you’ll need is the topographic kind—out in the wild, a tourist or road map will be all but useless.
How to Take a Compass Bearing
There are two easy methods you can use to navigate with a bearing. Before we get down to that, however, let’s first take a look at how to set your map.
Setting Your Map
Step 1: Adjust for Magnetic Declination
Your compass’s magnetized needle doesn’t actually point to True North. Instead, it points in the direction of Earth’s natural magnetic field, i.e. Magnetic North. This difference between the two is known as magnetic declination.
Declination values change over time and vary from region to region. As such, to take correct readings you must first adjust your compass for your area’s declination.
The declination value for the area should be located in the map’s legend. Depending on the declination value for the area, rotate the housing clockwise (west) or counterclockwise (east) until it’s set to the correct value at the index line, which is located at the base of the direction of travel arrow.
For example, if the declination value is 8° west, turn the housing 8° clockwise.
Warning: Always bear in mind that an east declination will be a positive number and a west declination will be a negative number.
Step 2: Align Your Map with True North
After adjusting for declination, place your compass on your map so the direction of travel arrow points north and the edge of the compass aligned against the edge of the map. Now, rotate the entire map and compass together until the red end of the magnetic needle is inside the orienting arrow.
You now have an accurately oriented map!
Taking a Sight Bearing and Triangulating Your Position
With your map and compass all set, you’re now ready to take a bearing. This simply means measuring the angle between Magnetic North, our current location, and a distant object in the terrain.
The easiest way to do so is with the visual or sight method, which allows you to locate your position using any easily identifiable landmark. Here’s how it’s done.
Step 1: Locate a Landmark
Hold the compass flat and steady. Point the direction-of-travel arrow toward a notable feature in the terrain. This could be a peak, river bend, the edge of a forest, a campsite, or any other easily identifiable landmark.
Step 2: Align the Magnetized Needle and the Orienting Arrow
Turn the bezel ring until the magnetic needle sits inside the orienting arrow. Read the bearing from below the index line.
Step 3: Adjust for Magnetic Declination
Unless you have a compass that allows you to “set it and forget it”, failure to do so means your reading will be out by the same number of degrees as the declination value for the area!
Step 4: Draw a Line from the Landmark Along the Bearing
Place the compass on the map, making sure that the orienting lines are parallel to the north-south grid lines. Position the compass so that the top end of the baseplate is at the landmark you’re targeting. Then draw a long line from the landmark following the bearing that you just took.
Step 5: Repeat Two Times and Triangulate
Repeat steps 1 to 3 two times with two additional landmarks or features. Your location will be within the triangle created where the three lines you have drawn intersect.
Plotting Your Course and Taking a Bearing
Now that you know your position, it’s time to plot a course to your destination.
While this step isn’t always necessary, it can help you navigate around obstacles (cliffs, steep inclines, boulder fields, lakes). It is also particularly useful when hiking in poor visibility, allowing you to break your journey up into small sections between waypoints (aka way-points/waymarkers) to make sure you stay on course.
Step 1: Identify Waypoints
Identify a sequence of easily identifiable landmarks or features between your starting point and destination and mark them on your map.
Step 2: Draw a Line Between Each Waypoint
Using the ruler edge and a pencil, draw a line between each waypoint to “connect the dots.”
Step 3: Take Your Bearings
Lay your compass on top of your topo. Place the edge of the baseplate along the line between point A (your current location) and point B (your first waypoint).
Turn the bezel so that the orienting lines align with the north-south grid lines, making sure that the north marker still points toward the upper part of the map. Read the bearing below the index line, adjust for declination, and repeat Step 3 for the successive legs of your journey (Point B to C, D, E, etc.).
Step 4: Follow Your Bearing
The bearings taken in Step 3 identify the specific direction in which you should travel in each leg of the plotted route.
Here’s how to follow each one, i.e. walk on a bearing.
Adjust your compass to the bearing taken for this leg of your journey, remembering to add/subtract the appropriate figure for declination. Now, hold in front of you and rotate your entire body until the magnetized needle lands inside the orienting arrow.
The direction that you’re now facing is the direction in which you must travel. To ensure you stay on course, we recommend keeping your compass in your hand while you walk. It’s also a good idea to identify smaller features in the distance you can navigate towards as intermediaries along the way.
Ready to Roll!
Didn’t we tell you it was easy?
Having read the above tutorial, we hope you heartily agree and can also see just how valuable a skill taking bearings can be when out in the wilds.
So what are you waiting for? Now that you’ve read the basics, it’s time to practice. With your instruments ready, get out there, and take some bearings!
How did you like our guide to taking a bearing? If you have any comments or want to tell us about your own experiences out in the field, feel free to leave a comment below. We’d love to know how it went!